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P0452 EVAP PRESSURE SIGNAL LOW CODE ON 2000 GMC 5.3 GAS
1 year 4 months ago #59632
by RonSgar
P0452 EVAP PRESSURE SIGNAL LOW CODE ON 2000 GMC 5.3 GAS was created by RonSgar
I WAS WORKING ON A 2000 GMC 1500 5.3 WITH A P0452 CODE FOR A PRESSURE SENSOR FAILURE. WHEN I UNPLUGGED THE SENSOR AND CHECKED 5V REFERENCE AND SIGNAL WIRE I GOT 5V ON BOTH. MY QUESTION IS THIS. WITH THE SENSOR PLUGGED IN VOLTAGE ON THE PRESSURE SENSOR SHOW 0 VOLTS. WHEN I UNPLUG THE SENSOR HARNESS FROM THE SENSOR THE SCANNER DATA WENT TO 2+ VOLTS. mY QUESTION IS, THE 2 + VOLTS IT SHOWED AFTER UNPLUGGING THE SENSOR, WAS THAT HALF OF THE 5V REFERENCE ON THE 5 V CIRCUIT? IT THAT A NORMAL CHANGE ON THE SCAN DATA. IF SO THEN JUST UNPLUGGING THE SENSOR WOULD TELL ME THAT THE SENSOR NEEDS TO BE REPLACED. NOT THAT IT WAS TOO HARD TO CHECK VOLTAGE READINGS, JUST CURIOUS WHERE THE 2+ VOLTS CAME FROM
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1 year 4 months ago #59638
by Cheryl
Replied by Cheryl on topic P0452 EVAP PRESSURE SIGNAL LOW CODE ON 2000 GMC 5.3 GAS
It’s a pull down sensor. The pcm sends 5 volts on the signal wire. Just like a cam sensor some are pull up some are pull down. Just have to check the voltage on the signal wire to 3 wire sensors unplugged
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1 year 4 months ago #59639
by RonSgar
Replied by RonSgar on topic P0452 EVAP PRESSURE SIGNAL LOW CODE ON 2000 GMC 5.3 GAS
Thanks Cheryl. Just never seen it before. Probably because I’ve never looked at the scan data when unplugged the sensor! Or can’t remember looking at it.
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1 year 4 months ago #59640
by Cheryl
Replied by Cheryl on topic P0452 EVAP PRESSURE SIGNAL LOW CODE ON 2000 GMC 5.3 GAS
Paul has a video of pull up and pull down on YouTube
The following user(s) said Thank You: RonSgar
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